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Scientists have photographed a giant gas bubble emanating from a whale, suggesting that flatulence is just as common for ocean mammals as it is for humans and many other terrestrial animals.

The picture, released last week by scientists from the Australian Antarctic Division (AAD) in Tasmania, was taken by the captain of a U.S. research ship the Nathaniel B. Palmer, while on expedition between Marguerite Bay and Palmer Station, Antarctica.

"The picture is of an Antarctic minke whale taken from the bow of a ship," said AAD principal research scientist Dr Nick Gales. "The white bits in the photo are pieces of ice-floe, the stream of pinky colour behind the whale is a faecal plume - a.k.a. "poo" - the large circle in the water is indeed the physical eruption of the whale's flatulence."

He and his colleagues are working to determine what it is that higher marine predators eat, and where they go to eat it. Instead of resorting to killing whales, the Australian Antarctic Division scientists have developed a method that allows them to collect whale faeces and study its DNA to figure out what the whale recently consumed.

The DNA work is linked to whale protection, since countries such as Norway, Iceland, and Japan have argued that whale numbers should be reduced to stabilise commercial fishing stocks.

"Sadly, some countries are promoting very simple interpretations of the way whale food consumption interacts with fishery yields, effectively arguing that if the whales did not eat those fish, then fishery yields would improve," Gales told Discovery News. "In reality, marine food webs are extremely complex and the relationship between what one of many predators eat, in this case whales, and a fishery yield is distant and may not even be direct."

He explained that whales also consume predators of many commercial species, and that other issues, including when and where whales eat, and what age class of a commercial species is affected by whales, complicate the debate.

Professor Daniel Costa, an expert in ecology and evolutionary biology at the University of California, Santa Cruz, agrees that whale numbers should not be further reduced by humans, their sole predator.

"The available data for whales suggests that their populations are well below the carrying capacity of the environment and thus there is no danger of them overeating their prey," said Costa.

Costa added, "The fate of whales is intimately associated with the fate of its prey."

He explained that whales' major prey, krill, a type of crustacean, is being reduced by climate change, which could cause problems for whales and many other Antarctic species that rely upon krill as a food source.

Gales, Costa, and several other scientists next month will study and tag Pacific whales and other animals in coordinated efforts to monitor individual species and to better understand the ocean food chain.